The instant invention is generally directed to the field of archery and archery arrows and, more specifically, to the field of vane structures on archery arrows to control arrow flight.
An arrow with no vanes flies fast—however, it also flies erratically. To reduce erratic flight, archers necessarily sacrifice a certain amount of flight speed through the application of arrow vanes. Vanes, which may be constructed from natural feathers or synthetic materials, are typically mounted in a plurality arrangement, parallel to the aft end of an arrow shaft. Notably, at the expense of a little flight speed, the vanes produce a certain amount of lift and side force on the arrow which advantageously serves to stabilize its flight pattern by moving the center of pressure aftwards, thereby increasing shot accuracy.
Generally speaking, the more surface area offered in a given vane, the more lift and side force that it introduces. There is a limit, however, on the practicality of simply increasing vane size for improved shot accuracy. For instance, larger vanes have a higher probability of interfering with bow components, such as an arrow rest, as the arrow is released from a drawn bow. The interference inevitably destabilizes the arrow flight, thereby negating any stabilization advantage offered by the increased surface area of the larger vane.
For conventional vanes, it is important that the vanes are installed precisely on the arrow shaft. Otherwise, bias away from the intended flight path of the arrow can be introduced from undesirable lift and/or side forces. Such undesirable bias can be negated by intentionally introducing a spin motion to the flight of the arrow. One way that spin may be introduced to an arrow is through vanes that have been fixed to the aft end of the arrow in an offset relative to the longitudinal axis of the arrow. In this way, as the arrow is projected forward on a path substantially in line with the arrow axis, the broad surface area of the vanes receive a force from the passing air that is translated to the arrow shaft on a vector offset from the arrow's longitudinal axis (i.e., a rolling moment), thereby causing the arrow to spin as it flies forward.
Another way that spin may be introduced to an arrow is through the application of vanes having a pre-curled profile that somewhat resembles the shape of a sail filled with wind. These pre-curled vane types may also be applied on an offset relative to the longitudinal axis of an arrow, as explained above. Notably, however, a possible advantage of a pre-curled vane profile over a “flat” vane is that the pre-curled vane, because it is curved, is significantly less stiff in the radial direction, which may reduce the forces imparted on the arrow in the event of an accidental collision of the vane with bow components during arrow launch.
Whether a “flat” vane or a “pre-curled” vane is used to introduce arrow spin, the amount of aerodynamic stability is limited by the overall vane height that can be accommodated when the arrow is released from a drawn bow. Simply put, taller vanes, while providing increased stability, are more prone to interfering with bow components as the arrow is released from a draw. To mitigate the detrimental effects on flight pattern that results from interference with bow components, flat vanes and pre-curled vanes alike are often made of flexible material. Flexible materials, however, allow the vane to deflect in flight, potentially reducing the total rolling moment that can be produced.
Additionally, because introduction of spin necessitates that vanes known in the art be positioned on an offset relative to the longitudinal axis of the arrow, it is a problem that vanes may be stressed, deformed or “kinked” as they are manipulated to mount on a cylindrical arrow shaft. This negative aspect is true of both flat vanes and pre-curled vanes presently known in the art.
Therefore, what is needed in the art is an arrow vane that can leverage stiff, high strength materials of construction for efficient transfer of energy with minimal risk of interference with bow components. Moreover, what is needed in the art is an arrow vane that can be communicated with the cylindrical shaft of an arrow without detrimentally affecting the vane shape or profile.
These, as well as other needs in the art, are addressed in the various embodiments of the invention as presented herein.